CVE-2016-7176 in Wireshark
Summary
by MITRE
epan/dissectors/packet-h225.c in the H.225 dissector in Wireshark 2.x before 2.0.6 calls snprintf with one of its input buffers as the output buffer, which allows remote attackers to cause a denial of service (copy overlap and application crash) via a crafted packet.
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Analysis
by VulDB Data Team • 09/15/2022
The vulnerability identified as CVE-2016-7176 represents a critical buffer manipulation flaw within Wireshark's H.225 dissector component, which is responsible for analyzing H.225 protocol traffic in telecommunications networks. This issue affects Wireshark versions 2.x prior to 2.0.6 and stems from improper handling of string formatting operations within the packet analysis framework. The flaw specifically manifests when the snprintf function receives one of its input buffers as the output destination, creating a scenario where memory regions overlap during string copying operations.
The technical implementation of this vulnerability involves a classic buffer overlap condition where the H.225 dissector in Wireshark incorrectly passes an input buffer as the destination parameter to snprintf. This misconfiguration causes the function to write data to memory locations that are already occupied by input data, resulting in unpredictable behavior including memory corruption and application instability. The vulnerability operates at the protocol dissection layer of Wireshark, meaning that when analyzing network traffic containing maliciously crafted H.225 packets, the application encounters a memory overlap scenario that leads to program termination.
From an operational perspective, this vulnerability presents a significant denial of service risk for network analysts and security professionals who rely on Wireshark for network traffic analysis. Attackers can craft specially formatted H.225 packets that, when processed by the affected Wireshark versions, will cause the application to crash and terminate unexpectedly. This disruption directly impacts network monitoring capabilities and can be exploited in scenarios where continuous traffic analysis is required. The vulnerability does not appear to enable arbitrary code execution or privilege escalation, but the denial of service impact is severe enough to compromise the availability of network analysis tools.
The flaw aligns with CWE-121, which addresses stack-based buffer overflow conditions, and demonstrates characteristics consistent with memory safety issues in network protocol parsers. From an ATT&CK framework perspective, this vulnerability maps to the T1059.007 technique related to command and scripting interpreter, as it exploits the application's handling of network input to cause system instability. The vulnerability also relates to T1498.001, which covers network denial of service attacks, since it enables remote attackers to disrupt network monitoring operations. Security professionals should note that this issue underscores the critical importance of proper buffer management in network protocol analysis tools, where input validation and memory handling are paramount to system stability.
Mitigation strategies for CVE-2016-7176 involve immediate upgrading to Wireshark version 2.0.6 or later, which contains the necessary patches to address the buffer overlap condition in the H.225 dissector. Network administrators should also implement network segmentation and monitoring to detect and prevent exploitation attempts, while security teams should consider temporary network traffic filtering to prevent potentially malicious H.225 packets from reaching analysis systems. The vulnerability serves as a reminder of the critical need for regular software updates and proper input validation in network analysis tools, as these systems often process untrusted data from network traffic and must maintain robust error handling to prevent exploitation.